Four wildlife groups are claiming that kangaroos are "on the brink of extinction" in three Australian states. If you read to the end of the article you find that that means they believe that "there are less than five kangaroos per square kilometre across most of NSW, South Australia and Queensland". OK, even accepting their figures on face value according to Wikipedia the land areas of these three state are 809,444 sq km, 1,043,514 sq km, and 1,852,642 sq km respectively, for a total of 3,705,600 sq km. In other words they believe that because kangaroo numbers between those three states have dropped below approximately 18,528,000 they are now "on the brink of extinction".